Veterinarians have no problem diagnosing advanced pituitary pars intermedia dysfunction (PPID, or equine Cushing’s disease)—the abnormally long hair coat that fails to shed (termed hypertrichosis) is about as telltale as clinical signs come in equine medicine. Confirming early stage PPID is decidedly more difficult, however, due to the subtle and vague signs it produces. Thus, researchers are continually working to identify new ways to both confirm early stage PPID and accurately classify research subjects.

At the 2014 American College of Veterinary Internal Medicine Forum, held June 4-7 in Nashville, Tennessee, Hal Schott II, DVM, PhD, Dipl. ACVIM, presented a poster detailing one of the new techniques researchers are exploring for PPID diagnosis: MRI.

A disease that affects all breeds and types of horses, PPID is caused by an enlargement of the pars intermedia in the pituitary gland, which is located at the base of the brain; essentially, as the pars intermedia enlarges, the horse’s clinical signs become more severe. This disorder occurs commonly in older horses, and the frequency of diagnosis generally increases with age. However, veterinarians have recognized PPID in some younger horses, as well.

Previously, Schott and colleagues showed that another form of imaging—computed tomography (CT scanning)—allowed veterinarians to visualize pituitary gland enlargement in PPID-affected horses; however, CT scanning was not able to provide details about the pars intermedia or anything else located within the pituitary gland